BMW ActiveHybrid 5 - Web Exclusive

Better mileage and more performance: the perfect compromise?

Hybrids have certainly earned their place on the automotive landscape, just not in the part occupied by enthusiasts, on the whole. Sure, they're cool, but it's safe to say that few Porsche, BMW, Jaguar or MB drivers ever gave a Hybrid owner the thumbs-up. So you can understand our alarm when we got dozens of thumbs-up and words of praise from Hybrid owners (specifically Prius drivers) during our two-day jaunt in the new BMW ActiveHybrid 5. Suffice to say, it was odd to be chased down by a Prius just so he could get a look at the Bimmer. And there were Insight owners as well, one followed us into gas stations to ask questions. We had entered the twilight zone.

In true Hybrid techno-geek fashion, they weren't concerned with our 0-60mph times or horsepower, but rather the holy MPG numbers. And needless to say, nearly all of them choked when they heard the figures: "What, only 23 city, 34 highway? that's horrible!"

To hypermilers, the Active 5 might not seem much of a planet-saver, but let's be honest; the hybrid unit in the Bimmer is as much for performance as economy. Don't believe us, how about BMW's claim of 0-60 in 5.7sec, which isn't shabby when you consider the big sedan tips the scales at a hefty 4375 lb!

Propulsion comes from the venerable N55 3.0-liter inline six force-fed by a single, twin-scroll turbo. Without electric assist, the motor churns out 302hp and 294 lb-ft across most of the powerband. But juiced by the electric motor, the combination makes 335hp and 335lb-ft thanks to 54hp and 154lb-ft from the motor. The combined number is lower than ultimate peak in order to preserve the drivetrain.

The ActiveHybrid 5 is a full-fledged hybrid and can run solely on electric power for roughly 2.5 miles up to 37mph thanks to its liquid-cooled electric motor sandwiched between the eight-speed transmission and gas motor by way of a clutch.

The electric mill is powered by a 0.68kw/hr 96-cell lithium-phosphate battery made by US company A123 Systems. It also utilizes brake regeneration technology.

Putting all hybrid stigma aside, BMW claims the battery will last as long as the car. The battery owes its longevity to being cooled by the air conditioning system's refrigerant, insulating it from high temps that ultimately shorten a battery's life.

BMW located the battery in the trunk between the rear wheels, which cuts cargo capacity by 30%, but still leaves enough space for all but the largest luggage.

An impressive hardware list is nothing without an extensive software package, and the ActiveHybrid 5 shines in this department. Along with gas-saving options like the auto stop/start feature that kills the engine at stoplights, the Five also features selectable driving modes like Sport, Comfort and Eco Pro, allowing the motor to decouple from the transmission and shut off at speeds up to 100mph (up from 50mph in all other settings). We can attest it's an eerie feeling to be cruising at 100mph with the engine off... technology is a wondrous thing.

Speaking of wondrous, the nav system is also a source of admiration, as its topographical information (when available) is continuously refreshed to maximize the hybrid's efficiency. For example, if the car is aware of a downhill stint following a hill, the engine will safely use more of its electricity reserves knowing it can regenerate downhill. However, if your hillclimb is followed by a flat stint, the car will automatically dial back how much juice it uses - it's amazing stuff.

All of the hardware and software adds up to a 300 lb weight penalty over a standard 535i, but the extra bulk is offset by a more efficient drivetrain that boosts mileage roughly 13% over the non-hybrid model.

Greater efficiency is only half the story, because the real tale is told from the driver's seat. The N55 engine has never been short of torque, but drive the ActiveHybrid 5 back-to-back with a standard 535i and the non-assisted variant feels weak until the upper reaches of the tacho. Thanks to 100% of the electric motor's 154 lbft available at will; the ActiveHybrid 5 has instantaneous throttle response that makes it feel like a torque-rich diesel off the bottom, backed by the top-end you'd expect from a boosted gas motor.

If there's one thing the ActiveHybrid 5 does well, it's eat miles. We conducted two 500-mile trips without a hitch, recording 32mpg at a steady 80mph on the highway, giving us a range of more than 500 miles. Trust us, you'll stop for a potty break long before running out of gas. Oh yeah, the cruise control sets at over 100mph - it's the little things that make European cars so special.

From the cockpit, the $8000 premium over a standard 535i, pushing the base MSRP to $61845, is justifiable thanks to the flexible powerplant(s) continually inducing a grin. But when potential buyers crunch numbers, questions may arise: How long will the 13% improvement take to pay for itself? Why didn't BMW mate the electric motor to a diesel? Do I really need a hybrid? All are valid questions and only a prospective owner can answer. Sure, BMW could have designed it to get even better gas mileage, but that might have compromised the driving experience, and that's not what BMW does. Instead, the company has proven that even a Hybrid can be exciting and, more importantly, even a Hybrid can be a performance vehicle. If this is a sign of things to come, we eagerly await what lies ahead.